Lubricant heating system for turbosuperchargers and the like



Nov. 6, 1945. J. c. BUECHEL 9 9 LUBRICANT HEATING SYSTEM FOR TURBOSUPERCHARGES AND THE LIKE Filed June 3, 1942 Fig, l.

AMPLIFIER AND RELAY AMPL/F/ER AND RELA Y Inventor: Joseph QBuecihel Hls Attorvney.

Patented Nov. 6, 1945 LUBRICANT HEATING SYSTEM FOR TURBO- SUPEKCHARGERS AND THE LIKE Joseph C. BuecheLHollywood, Calif., assignor to General Electric Company, a corporation New York Application June 3, 1942, Serial No. 445,590

4 Claims.

The present invention relates to lubricant heating systems and especially to lubricant heating systems for turbosuperchargers, although it is not limited thereto necessarily but may be used wherever found applicable.

The objectof my invention is to provide an improved lubricant heating system which is. simple in structure, reliable in operation'and functions automatically. 1 I I For a consideration of what I. believe to .be novel andmy invention, attention is directed to the following specification and the claims appended thereto. g

In the drawing-Fig.1 is a diagrammatic view of a system, embodying my invention, and Fig. 2 is a similar view of a modiflcation Referring to the drawing, Fig. l, 3 indicates a turbosupercharger' comprising ,an exhaust. gas driven turbine 4, and a compressor 5,. The turbine wheel is indicated at 6, the nozzle box at l, the exhaust gas inletatll, and the waste, gate valve at 9. The compressor inlet is indicated at H! and the compressor discharge isindica'ted at II. Lubricant is suppliedto the parts orthe turbosupercharger requiring lubrication by a pressure oil pump I2 which has its inlet connected to a lubricant supply. tank I3, by. a pipe line I4. The pump I2 supplies lubricant through suitable passages to parts of the supercharger requiring lubrication. From such parts the lubricant flows to a suitable sump in the supercharger casing (not shown). The lubricant is returned from the sump to tank I3 by a scavenger pump Iwhich has its discharge connected to tank I3 by a pipe line I6. The pressure and scavenger pumps may be driven from the turbosupercharger shaft through suitable gearing.

The structure so far described is a known one and is to be taken as typical of any turbosupercharger installation. In the case of an aircraft, the turbine 4 may be operated by exhaust gases from an aircraft engine. The compressor 5 may be used to supercharge an aircraft engine, a cabin, or for other purposes.

In installations of'this type difficulty is experienced sometimes with the lubricant reaching such a low temperature that it does not flow readily. This condition may obtain in cold weather when the aircraft is on the ground. Also, it may occur when the aircraft is at a high altitude and the engine is temporarily shut down so that the supercharger ceases to operate for a short time, but a time long enough that the oil in the tank and in the pipe line may become cold.

According to the Fig. 1 embodiment of my invention, I provide in tank I3 a suitable electric heating unit Il connected to a source of electrical energy I8 by conductors I9 and 20. In conductor 20 is an electric switch 2| whichis normally open.

When closed, it connects source l8 to.heating unit I1. I then provide a pump 22, independent of pressure pump I2, for circulating the lubricant in tank I3 through the tank and the pipe lines I4 and I6, and provide means responsive to the temperature of the lubricant being circulated ,for controlling such circulation. ,In the arrangementshown in Fig. 1, pump 22 is a continuously running pump driven by any suitable means such as an electric motor, for example. It is connected in shunt to pump I2 by a suction or inlet pipe 23 which connects the inlet of pump 22v to pipe line I4, and by a dischargepipe 24 which connects the discharge side of pump22 to pipe line I 6. Pipes 23 and 24 are connected to pipe lines [4 and I6, respectively, at points adjacent to pressure pump I2 and'scavenger. pump I5. In pipe 23 is a normally closed valve 25 which is biased to closed position by a spring 26 and which is adapted to be opened against the action of spring 26 by a solenoid 21, the winding of which is connected to source I8 by conductors 28 and 29. In conductor 29 is a switch 30 which is normally open and whichwhen closed energizes solenoidZ'I to effect the opening of valve. 25. .Valve 25 may be of any suitable type. In the present instance; it is shown as comprisingf'a valve body 3| which slides in thevalve casing and has a passage 32 which is normally out of line with pipe 23 and is brought into line therewith when solenoid 21 is energized.

Switches 2| and 3B are closed by a solenoid 33 which is in circuit with a temperature responsive device 34 associated with pipe line I4.

Any suitable type of temperature responsive device may be used, the essential thing being that it effects a closing of switches 2| and 30 by solenoid 33 whenever the temperature of the oil in pipe line I4 is below a predetermined low value and eflects opening of such switches when the temperature of oil in pipe line I4 is above such predetermined value. In the present instance, temperature responsive device 34 is indicated as being in the form of a thermocouple connected to solenoid 33 through the intermediary of a suitable amplifier and relay 35 which controls-the connection between solenoid 33 and source I3. The i put conductors between the thermocouple 34 and the amplifier and relay 35 are indicated at 3B and the power conductors between source l8 and the amplifier and relay 35 are indicated at 31. In

conductors 31 is a hand switch 38. Solenoid 33 is connected to the output circuit of amplifier and relay 35 by conductors 39.

In pipe 24 is a non-return valve 40 which prevents fiow of lubricant from pipe line l6 toward pump 22 and in pipe line I 6 is a non-return valve 4| which prevents flow of lubricant through pipe line I6 toward pump I5.

In normal operation, hand switch 38 is closed so as to put power on the amplifier and relay 35. Now, if the temperature of the oil in pipe line 14 is below the desired low value, .switch 2| connects heater element I! to source 18 and switch 30 connects solenoid 21 to source I 8. Pump 22 is a continuously running pump :and when solenoid 21 is energized, valve 25 is actuated to open pipe 23 so that pump 22 circulates lubricant from tank l3 through pipe lines [4 and [Shack tothe tank, the circulation being in shunt to pumps l2 and l 5. By reason of the fact that pipes 23 and 24 are connected adjacent to pumps. l2 and I5, circulation of lubricant takes place throughout substantially the entire pipe line. When the temperature of the lubricant in the system reaches a predetermined high value, thermocouple 34 effects operation of solenoid 33 to open switches 2| and 30, thus disconnecting heater I! from source I8 and shutting off thesuction inlet of pump 22 whereupon pump 22 will run idle.

In Fig. 2 is illustrated a modification similar to that shown in Fig. .1 except that pump 22%, corresponding to pump 22 of Fig. 1, is operated by an electric .motor 42, the circuit of which is controlled by a switch 30, corresponding to switch 30 of Fig. 1. Otherwise, the arrangement indicated in Fig. 2 is the same as that shown in Fig. 1 and corresponding reference characters have been used to indicate corresponding Parts. With the arrangement shownin Fig. 2, pump 22 is shut down when the lubricant has 'thedesired high temperature rather than having its inlet closed, as shown in Fig. 1.

By my invention, I provide a system which is simple in structure and which operates automatically to maintain the lubricant in the system above a desired temperature.

In accordance with the provisions of the patent statutes, 1 have described the principle of operation of my invention, together with the apparatus which I now consider to represent .the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a turbosupercharger, a lubricant tank, pump means connected with said tank for .conveyinglubricant from the tank to turbosupercharger parts requiring lubrication and thence back to the tank, a second pump means in shunt to said first-named pump means for effect- .ingcirculation of lubricant from and back to the tank, a heating element in the tank, and means responsive to the temperature of the lubricant for controlling said'heating element and the circulation of lubricant by said second pump means.

2. In combination, a turbosupercharger, lubricant pump means driven by the turbosupercharger, a lubricant tank, a suction pipe line and a return pipe line between said tank and said pump means, a second pump means in shunt'to said first-named pump means .for effecting circulation'of lubricant through said tank-and said pipe lines, a heater in said tank, and means .controlled by the temperature .of the oil foreifecting operation of said second pump means and for controlling said heater.

3. In a mechanism subjected to low temperatures, the combination of a machine to be lubricated, a lubricating system for the machine comprising a lubricant supply tank, lubricant pump means, and a suction pipe line and areturn pipe line connecting said tank to said pump means, a heater associated with said lubricating system, a second pump means in shunt tosaid first-named pump means, and means controlled by the temperature of the lubricant for controllingsaid second pump means and said heater.

4. In combination, .a machine to be lubricated, a lubricant pump means driven by'said machine,

a lubricant tank, a suction pipe .line .and a return pipe line connecting the tank to said pump means, a pump connected inshunt to said lubricant pump means for efiecting circulation of lubricant through said tank and pipe lines, an

electricheater in said tank-andmeans controlled by .the temperature of the lubricant for controlling circulation .of lubricant by said pump and for controlling said electric heater.

JOSEPH C. BUECHEL. 

